1 files changed, 78 insertions, 9 deletions

diff --git a/arch/riscv/kvm/aia_imsic.c b/arch/riscv/kvm/aia_imsic.c
index 6cf23b8adb71..e597e86491c3 100644
--- a/arch/riscv/kvm/aia_imsic.c
+++ b/arch/riscv/kvm/aia_imsic.c
@@ -9,13 +9,14 @@
 
 #include <linux/atomic.h>
 #include <linux/bitmap.h>
+#include <linux/irqchip/riscv-imsic.h>
 #include <linux/kvm_host.h>
 #include <linux/math.h>
 #include <linux/spinlock.h>
 #include <linux/swab.h>
 #include <kvm/iodev.h>
 #include <asm/csr.h>
-#include <asm/kvm_aia_imsic.h>
+#include <asm/kvm_mmu.h>
 
 #define IMSIC_MAX_EIX	(IMSIC_MAX_ID / BITS_PER_TYPE(u64))
 
@@ -55,6 +56,7 @@ struct imsic {
 	/* IMSIC SW-file */
 	struct imsic_mrif *swfile;
 	phys_addr_t swfile_pa;
+	raw_spinlock_t swfile_extirq_lock;
 };
 
 #define imsic_vs_csr_read(__c)			\
@@ -613,12 +615,23 @@ static void imsic_swfile_extirq_update(struct kvm_vcpu *vcpu)
 {
 	struct imsic *imsic = vcpu->arch.aia_context.imsic_state;
 	struct imsic_mrif *mrif = imsic->swfile;
+	unsigned long flags;
+
+	/*
+	 * The critical section is necessary during external interrupt
+	 * updates to avoid the risk of losing interrupts due to potential
+	 * interruptions between reading topei and updating pending status.
+	 */
+
+	raw_spin_lock_irqsave(&imsic->swfile_extirq_lock, flags);
 
 	if (imsic_mrif_atomic_read(mrif, &mrif->eidelivery) &&
 	    imsic_mrif_topei(mrif, imsic->nr_eix, imsic->nr_msis))
 		kvm_riscv_vcpu_set_interrupt(vcpu, IRQ_VS_EXT);
 	else
 		kvm_riscv_vcpu_unset_interrupt(vcpu, IRQ_VS_EXT);
+
+	raw_spin_unlock_irqrestore(&imsic->swfile_extirq_lock, flags);
 }
 
 static void imsic_swfile_read(struct kvm_vcpu *vcpu, bool clear,
@@ -664,6 +677,60 @@ static void imsic_swfile_update(struct kvm_vcpu *vcpu,
 	imsic_swfile_extirq_update(vcpu);
 }
 
+bool kvm_riscv_vcpu_aia_imsic_has_interrupt(struct kvm_vcpu *vcpu)
+{
+	struct imsic *imsic = vcpu->arch.aia_context.imsic_state;
+	unsigned long flags;
+	bool ret = false;
+
+	/*
+	 * The IMSIC SW-file directly injects interrupt via hvip so
+	 * only check for interrupt when IMSIC VS-file is being used.
+	 */
+
+	read_lock_irqsave(&imsic->vsfile_lock, flags);
+	if (imsic->vsfile_cpu > -1) {
+		/*
+		 * This function is typically called from kvm_vcpu_block() via
+		 * kvm_arch_vcpu_runnable() upon WFI trap. The kvm_vcpu_block()
+		 * can be preempted and the blocking VCPU might resume on a
+		 * different CPU. This means it is possible that current CPU
+		 * does not match the imsic->vsfile_cpu hence this function
+		 * must check imsic->vsfile_cpu before accessing HGEIP CSR.
+		 */
+		if (imsic->vsfile_cpu != vcpu->cpu)
+			ret = true;
+		else
+			ret = !!(csr_read(CSR_HGEIP) & BIT(imsic->vsfile_hgei));
+	}
+	read_unlock_irqrestore(&imsic->vsfile_lock, flags);
+
+	return ret;
+}
+
+void kvm_riscv_vcpu_aia_imsic_load(struct kvm_vcpu *vcpu, int cpu)
+{
+	/*
+	 * No need to explicitly clear HGEIE CSR bits because the
+	 * hgei interrupt handler (aka hgei_interrupt()) will always
+	 * clear it for us.
+	 */
+}
+
+void kvm_riscv_vcpu_aia_imsic_put(struct kvm_vcpu *vcpu)
+{
+	struct imsic *imsic = vcpu->arch.aia_context.imsic_state;
+	unsigned long flags;
+
+	if (!kvm_vcpu_is_blocking(vcpu))
+		return;
+
+	read_lock_irqsave(&imsic->vsfile_lock, flags);
+	if (imsic->vsfile_cpu > -1)
+		csr_set(CSR_HGEIE, BIT(imsic->vsfile_hgei));
+	read_unlock_irqrestore(&imsic->vsfile_lock, flags);
+}
+
 void kvm_riscv_vcpu_aia_imsic_release(struct kvm_vcpu *vcpu)
 {
 	unsigned long flags;
@@ -691,9 +758,8 @@ void kvm_riscv_vcpu_aia_imsic_release(struct kvm_vcpu *vcpu)
 	 */
 
 	/* Purge the G-stage mapping */
-	kvm_riscv_gstage_iounmap(vcpu->kvm,
-				 vcpu->arch.aia_context.imsic_addr,
-				 IMSIC_MMIO_PAGE_SZ);
+	kvm_riscv_mmu_iounmap(vcpu->kvm, vcpu->arch.aia_context.imsic_addr,
+			      IMSIC_MMIO_PAGE_SZ);
 
 	/* TODO: Purge the IOMMU mapping ??? */
 
@@ -748,7 +814,7 @@ int kvm_riscv_vcpu_aia_imsic_update(struct kvm_vcpu *vcpu)
 		/* For HW acceleration mode, we can't continue */
 		if (kvm->arch.aia.mode == KVM_DEV_RISCV_AIA_MODE_HWACCEL) {
 			run->fail_entry.hardware_entry_failure_reason =
-								CSR_HSTATUS;
+								KVM_EXIT_FAIL_ENTRY_NO_VSFILE;
 			run->fail_entry.cpu = vcpu->cpu;
 			run->exit_reason = KVM_EXIT_FAIL_ENTRY;
 			return 0;
@@ -769,13 +835,16 @@ int kvm_riscv_vcpu_aia_imsic_update(struct kvm_vcpu *vcpu)
 	 * producers to the new IMSIC VS-file.
 	 */
 
+	/* Ensure HGEIE CSR bit is zero before using the new IMSIC VS-file */
+	csr_clear(CSR_HGEIE, BIT(new_vsfile_hgei));
+
 	/* Zero-out new IMSIC VS-file */
 	imsic_vsfile_local_clear(new_vsfile_hgei, imsic->nr_hw_eix);
 
 	/* Update G-stage mapping for the new IMSIC VS-file */
-	ret = kvm_riscv_gstage_ioremap(kvm, vcpu->arch.aia_context.imsic_addr,
-				       new_vsfile_pa, IMSIC_MMIO_PAGE_SZ,
-				       true, true);
+	ret = kvm_riscv_mmu_ioremap(kvm, vcpu->arch.aia_context.imsic_addr,
+				    new_vsfile_pa, IMSIC_MMIO_PAGE_SZ,
+				    true, true);
 	if (ret)
 		goto fail_free_vsfile_hgei;
 
@@ -962,7 +1031,6 @@ int kvm_riscv_vcpu_aia_imsic_inject(struct kvm_vcpu *vcpu,
 
 	if (imsic->vsfile_cpu >= 0) {
 		writel(iid, imsic->vsfile_va + IMSIC_MMIO_SETIPNUM_LE);
-		kvm_vcpu_kick(vcpu);
 	} else {
 		eix = &imsic->swfile->eix[iid / BITS_PER_TYPE(u64)];
 		set_bit(iid & (BITS_PER_TYPE(u64) - 1), eix->eip);
@@ -1039,6 +1107,7 @@ int kvm_riscv_vcpu_aia_imsic_init(struct kvm_vcpu *vcpu)
 	}
 	imsic->swfile = page_to_virt(swfile_page);
 	imsic->swfile_pa = page_to_phys(swfile_page);
+	raw_spin_lock_init(&imsic->swfile_extirq_lock);
 
 	/* Setup IO device */
 	kvm_iodevice_init(&imsic->iodev, &imsic_iodoev_ops);